Experience with continuous ambulatory EEG monitoring

The value of continuous ambulatory EEG monitoring in the management of patients with seizures was assessed. Eighty-seven patients were studied over a two-year period, and 198 recordings were made. In six patients data from the monitor record changed management significantly by suggesting a diagnosis other than that made clinically and by routine EEG. In a further 33 patients data strongly supporting the clinical diagnoses were obtained. In 47 patients no positive diagnostic data were obtained, and in one patient the data could not be reconciled with the clinical picture. The ambulatory EEG was particularly useful for detecting nocturnal fits, such as tonic seizures, and for differentiating genuine seizures from pseudoseizures. Limitations of the instrument include the presence of only four channels and some distortion and degradation of the EEG signal. In spite of these problems, the instrument was found to be a valuable aid in the evaluation of patients with seizures.